Step 1: Crafting the Perfect Crust
- Crush the Oreo cookies into fine crumbs using a food processor or by placing them in a ziplock bag and crushing them with a rolling pin.
- In a mixing bowl, combine the crushed Oreos with espresso powder and melted butter. Mix until well coated.
- Press the mixture evenly into a 9-inch springform pan lined with parchment paper.
- Place the crust in the freezer while you prepare the filling.
Step 2: Preparing the Creamy Cheesecake Filling
- In a large mixing bowl, beat the softened cream cheese, mascarpone cheese, sour cream, cold heavy cream, powdered sugar, vanilla extract, and instant pudding mix using an electric hand mixer.
- Mix until the batter is smooth, creamy, and fully combined.
Step 3: Assembling the Tiramisu Layers
- Remove the crust from the freezer and spread ⅓ of the cheesecake filling evenly over it.
- Quickly dip the ladyfingers in espresso (and Kahlua if using), ensuring they are soaked for less than a second to avoid sogginess.
- Arrange the soaked ladyfingers in a single layer over the cheesecake filling.
- Spread a thin layer of cheesecake filling over the ladyfingers and smooth it out with a spatula.
- Transfer the remaining cheesecake filling to a piping bag with a star tip and pipe decorative dollops over the top.
Step 4: Chilling & Finishing Touches
- Cover the cheesecake with plastic wrap and refrigerate for at least 4 hours (or overnight for best results).
- Before serving, remove from the pan and generously dust the top with cocoa powder.